This invention relates to a cassette insertion opening structure for inserting a cassette, in which a stimulable phosphor is stored, into a radiation image reading apparatus and also relates to the apparatus on which the insertion opening is provided.
In the past, a stimulable phosphor sheet that is stored in a box-shaped cassette has been used in order to record radiation images which are typically X-ray images for the purpose of medical diagnosis and the like. The stimulable phosphor sheet is one in which a layer of a stimulable phosphor is formed on a support and covered with a protective layer. The stimulable phosphor accumulates radiation energy such as the irradiated X-rays and the like, and also releases the stored energy as photo-stimulated luminescence by irradiating excitation light of a prescribed wavelength.
Generally, after a radiation image is recorded on the stimulable phosphor sheet that is stored in the cassette using the radiographing device, the radiation image recorded on the stimulable phosphor sheet is outputted to a film using an outputting device, and/or the radiation image is displayed as a visible image on a display device.
A radiation image reading device which reads out the radiation image from the stimulable phosphor sheet is used in order to output the radiation image on the stimulable phosphor sheet as a visible image. Examples of the radiation image reading apparatus include those disclosed in Patent Documents 1, 2, and 3. In each of these radiation image reading apparatuses, a light scanning unit for irradiating a scanning beam on the stimulable phosphor sheet and a sensor unit for electrically reading the photo-stimulated luminescence emitted from the stimulable phosphor sheet by means of a scanning beam are provided inside the housing. In addition, an insertion opening is formed on the housing and the cassette is inserted into the housing through the insertion opening.
However, because the insertion opening is formed as narrow and rectangular, when the cassette is inserted into the insertion opening, positioning of the cassette at the insertion opening is difficult. That is to say, the cassette must be aimed at the insertion opening for insertion therein and thus the cassette cannot be easily handled for inserting it into the insertion opening.
[Patent Document 1] Unexamined Japanese Patent Application Publication No. Tokkai 2004-101988
[Patent Document 2] Unexamined Japanese Patent Application Publication No. Tokkai 2004-102066
[Patent Document 3] Unexamined Japanese Patent Application Publication No. Tokkai 2004-102078